Dior So Real - Tilda Swinton - A Bigger Splash

Actress Tilda Swinton wears two pairs of Dior sunglasses in A Bigger Splash (2016). The main pair is the silver Dior Futurist (read more here), but she also wears these black Dior So Real sunglasses.

Dior So Real sunglasses are available in different color combinations, and have a different color painted on the top part of the lenses, see the product photo on the left. That's not a refelection on the lens, that's actually a different color (although it is a bit transparent so it doesn't block your view). It can be seen in the screenshot from the film as well if you look closely.

Dior So Real is a popular model and also worn by Chris Brown in the music video Five More Hours (although in a different color combination).

Reference: Dior So Real black, B0YMD